1. Field of the Invention
The present invention relates to an antenna device for a radio communications apparatus operating in the frequency range of 800-3000 MHz and including a radiator.
2. Related Art
On small portable radio communications apparatus, so-called mobile telephones, use has previously been made of a plurality of different antenna types, including rod antennas of the quarter wave or half wave type, helix antennas, etc. One common denominator for all of these prior art designs and constructions is that attempts have been made to keep the physical dimensions of the antenna as small as possible, the degree of efficiency as high as possible and the band width as large as possible. Certain antenna types have proved to be successful in one or two of these respects, but no truly optimum design and construction has yet been developed.
In particular in such situations where transmission and reception take place at great distances in terms of frequency, it is important that the antenna is of the wide band type.